The present invention relates to a survey apparatus and a survey method. More particularly, the preferred embodiments of the present invention relate to a laser survey apparatus and a survey method using a laser survey apparatus for use in the underground mining industry.
Current methods for the survey control of azimuth and grade in an underground mine during excavation of a tunnel in the mine typically involve the use of survey stations installed in a manner whereby the bearing between the survey stations is generally set to correspond to the bearing of the heading required for excavation.
The survey stations are typically comprised of two eye bolts installed in the roof of the heading in the underground mine along the centre line of excavation of the heading. Two wires are usually strung from the eye bolts and have a weight tied to the bottom of each wire. A mine worker can subsequently sight through the wires and mark a centre line at the working face of the excavation.
Grade control is usually achieved through the installation of four eye bolts in the walls of the tunnel. These eye bolts are joined in pairs by wires and a mine worker is able to sight through these wires and mark an offset floor height at the working face of the excavation.
Unfortunately, the nature of underground mining and the constraints placed upon its workers lead to a variety of problems.
The eye bolts are easily damaged by machinery or the destructive effects of blasting. The wires also utilised in the survey stations are commonly broken as a result of not being wound up after use. Further, the ventilation in use in underground mines typically causes the installed wires to sway when hanging from the roof of the heading. This swaying movement results in inaccuracies when sighting. The very method of sighting introduces an unacceptable level of human error and requires operation by particularly skilled workers to be effective.
The requirement for the use of wires in current methods can result in a less skilled or an inattentive mine worker incorrectly determining the line and grade in an excavation.
Relatively recent developments include the utilisation of lasers for the alignment of development headings. Methods utilising lasers used to this point have been labour and time intensive, and can result in damage to the lasers. In addition, a front target has traditionally been required for accuracy confirmation and adjustment. At least in part because of these reasons, lasers have generally only been used to this point if a heading is going to be beyond a certain length, for example 100 metres.
Unfortunately, shorter headings do form the majority of such work. However, some recent work has been conducted utilising pen-sized lasers in headings less than 100 metres. However, the mounting of such a laser on the walls of a heading require brackets and bolting, taking a significant amount of time to set up or establish, are not received easily and are similarly not adjusted easily.
The temperamental nature of lasers and their mountings has required complicated checking systems to ensure that the laser has not moved from its original position.
Still more recent developments have included the mounting of a laser in a PVC tube of a size big enough to hold the entire laser within the PVC tube, in a pre-drilled aperture in a strata face. The pre-drilled aperture is partially filled with chemical grout and the PVC tube containing the laser is inserted into the aperture. The curing of the grout in this arrangement typically moves the pipe and laser from their original alignment. As such, recalculation of the target is generally required.
A further problem associated with this arrangement is the switching on/off of the laser. The mounting method utilised does not allow access to the laser when in position.
The present invention attempts to overcome one or more of the disadvantages of the prior art.
According to the present invention there is provided a survey apparatus comprising:
a mounting means adapted to be mounted on a fixed object; and
an alignment means adapted to releasably engage with the mounting means,
wherein the alignment means is capable of operating when the alignment means is engaged with the mounting means.
Preferably, the alignment means is provided therein a switch means. The switch means is preferably actuated upon receival of the alignment means in the mounting means, thereby causing operation of the alignment means.
The alignment means may include a laser means and the alignment means may also include a battery means.
Still further, the alignment means is preferably provided with a mechanism to releasably lock the alignment means in position with respect to the mounting means.
The mounting means is preferably formed with a cone-shaped first end to facilitate penetration into an epoxy resin used to locate the mounting means within a fixed surface. An outer surface of the mounting means may be provided with a portion or portions thereof knurled and/or grooved to facilitate grip with the epoxy resin.
The mounting means further preferably comprises a biasing means that acts to bias the alignment means out of the mounting means.
The alignment means preferably supports the laser means in an adjustable manner, preferably by way of an array of adjustable screws, whereby selective adjustment of the screws being able to adjust alignment of the laser means.
According to the present invention there is preferably provided a method of survey control comprising the following steps:
making an aperture in a fixed surface for receiving a mounting means;
connecting an alignment means to the mounting means,
wherein connecting of the alignment means to the mounting means operates the alignment means.